Fasting Blood Glucose

Fasting glucose does not translate directly into an A1c value. Standard metabolic panels commonly include fasting glucose but not fasting insulin. Fasting glucose can remain normal for many years while insulin resistance worsens. Fasting glucose is a snapshot that can vary substantially depending on when it is measured. Fasting glucose alone can miss compensatory hyperinsulinemia. Evidence cited in the article indicates glycaemic risk may be non-linear in diabetes and CKD. Fasting blood glucose is measured after at least 12 hours without food. Fasting glucose captures the lowest point of the daily glucose curve rather than the average. Meal composition strongly affects post-meal glucose behavior in a way fasting glucose alone does not reveal. Hyperglycaemia and impaired fasting glucose can contribute to hyperfiltration, intraglomerular hypertension, albuminuria, and reduced glomerular filtration. Hyperglycaemia promotes oxidative stress, inflammation, and vascular cell damage. A normal fasting glucose can coexist with post-meal spikes that produce a pre-diabetic average glucose. Low fasting glucose below 70 mg/dL is described as problematic only when ketones are absent. The articl…